The present invention relates broadly to earth boring equipment and, more particularly, to a reinforced earth boring rod assembly and a method for producing the same.
The installation of utilities, such as underground electrical cable and cable television, typically involve horizontal boring, known also as "moleing." This operation consists of utilizing rotating lengths of segmented drive rods which are powered from an above-ground power source to drive a drill bit or compaction head.
The drive rods are fixed at one end with a continuation segment which may be a hex-shaped female end or a hex-shaped male end for receipt within the female end. Either of these rods may be mounted, typically by welding, to an existing boring rod to provide a link thereby rod segments may be joined. Further, the compaction head or boring bit may be inserted in a female end portion.
During use, such rods are typically affected by twisting forces due to the resistance of the earth as the power source rotates the driving rod as well as bending forces due to rod movement along its length and compressive forces as the rod is forced inwardly into the earth. These forces can weaken the junction between rod end and the boring rod segment. In addition, heat applied during the welding of the junction between the drive rod and the rod end can weaken the soft steel material of the drive rod. Heretofore, such boring rods have been noted for their ability to fail during field operations which can be time consuming and typically results in increased expense for the boring operation.